<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
    <!-- 接收用户输入的年份，如果是闰年就弹出闰年，否则弹出是平年 -->
    <script>

        var year = prompt("请输入年份：");
        if (year % 4 == 0 && year % 100!= 0 || year % 400 == 0) {
            alert(year + "是闰年");
        } else {
            alert(year + "是平年");
            }
    </script>
</body>
</html>